Initial experience with a dedicated cardiac MRI program for congenital heart disease in a limited resource environment

Abstract

Introduction: Poor awareness, infrastructural costs and need for expertise have limited use of cardiac magnetic resonance imaging (CMR) for congenital heart disease (CHD) in India and other developing nations despite its rapidly growing acceptance internationally. Objectives: To discuss clinical impact, challenges and pitfalls in establishing a CMR program for CHD in India. Methods: Dedicated CMR unit for CHD was established in January 2010 comprising 1.5 Tesla GE scanner, dedicated personnel (Pediatric Cardiologist and Cardiac Radiologist). All patients undergoing CMR were prospectively included in a database. Results: Hundred patients; median age: 11 years (1year-65years) underwent CHD-CMR (January 2010 - August 2011). Twenty required general anesthesia. 56% had unoperated or palliated complex CHD, including 11 with complex double-outlet right ventricle (DORV); 33% were older than 10 years. Protocols for sequences and imaging planes were customized according to information desired. Accurate anatomical information (intracardiac and extracardiac) was obtained in all. In 10%, new anatomic details (not identified by other modalities) were noted. Physiological information obtained included ventricular function, shunt ratios, and blood flow dynamics. Data withstood internal cross-validation in 97%. Additional imaging was requested-for in 4 patients after CMR. 19 underwent cardiac surgery on basis of information obtained/augmented by CMR, including double-switch (Senning + Rastelli) (2), conversion after Glenn shunt to biventricular repair in complex DORV (3), direct 2-ventricle repair in complex DORV (2), conduit placement/ replacement (3), Bentall operation (1), Fontan (3). Complex repairs were significantly aided by CMR. Challenges included need for specialized training, learning curve influenced by a unique patient-subset, relatively long procedure (45-90 min) and post-processing time, logistics of sharing MRI scanner with radiology, poor initial acceptance by professional colleagues, and financial considerations. Conclusion: Cardiac MRI is a powerful tool in assessment and follow-up of complex CHD. In developing nations like India, with large burden of older children/adults with complex unoperated lesions, CMR can play critical role in planning management. Establishment of a dedicated CHD-CMR unit is feasible and advantageous in a center looking after patients with CHD.